This invention relates to an anti-rust cover for a disc rotor in a disc brake used for a vehicle, more particularly, to one which is improved in its attachability in place by enhancing the resilience thereof by means of forming a detoured path portion, on a bridge portion which is made into an arcuate form in a portion of the anti-rust cover, in a manner of projecting outwardly from the arcuate bridge portion, and also improved in its handling or operational feature, when it is detached, by means of allowing the anti-rust cover to be easily broken away or torn off at the just mentioned detoured path portion.
A disc rotor in a vehicle disc brake, which is rotated in a body which a wheel, is usually made of cast iron, so it is highly likely to rust. Especially when a vehicle with such a disc rotor is exported in an ocean going steamer, it is often subjected to sea wind containing much salt while it is in waiting for the loading at the pier. Thus, the disc rotor is very likely to be rusted.
The rust produced on the surface of the disc rotor causes the brake pad urging the same to be worn out in a short period and the friction coefficient to decrease, accompanying a byproblem of deterioration of the braking performance. As a measure of anti-rusting, an application of anti-rusting treatment on the surface of the disc rotor is generally thought of. Coating of an anti-rusting material, for example, on its surface may result in a deficiency of the braking force through the decreasing of the friction coefficient of the rotor surface. It is, therefore, by no means desirable that the disc rotor in the unloaded vehicle in the importing land still has a remnant of anti-rusting material on it when the vehicle be handed over to the customer. If the anti-rusting material is removed earlier than the vehicle is delivered, the above-mentioned problem of rust-producing remains unsolved. For this reason, the coating of an anti-rusting material is usually regarded as impracticable. A usual way of preventing the rust, instead of the coating, has been to cover the disc rotor in order to physically protect it from the cause of rusting.
The general conventional practice has been therefore to attach an annular shaped anti-rust cover made of synthetic resin or cardboard to the dust cover, which is usually secured within a wheel on the inner side of the disc rotor (nearer to the center of the chassis), in order to cover the outer side of the disc rotor. This anti-rust cover, being attached on the outer periphery of the dust cover to cooperate therewith in enveloping the disc rotor for preventing the salty sea wind ingressing or flowing into the coverage, attains the aim of anti-rusting.
This known anti-rust cover is place temporarily, not being permanent use, i.e., the anti-rusting effect is provided while the vehicle is in the ocean going transportation route. Consequently, the anti-rust cover must be attached before the transportation and removed after the transportation after the main period during which the disc would be otherwise subjected to rusting is over, that is, prior to the delivery to the customer. For that purpose of removing, when it becomes unnecessary, an idea of making a slit in the bridge portion, where the annular portion of the anti-rust cover is partly narrowed, is practiced. It will make that portion of the anti-rust cover easy to be broken or torn only by pulling it when it must be removed. Formation of such a slit is inherently accompanied by some problems such as, possible variation of the size thereof which is liable to cause an undesirable breakage of the anti-rust cover when it is being attached to, unexpected difficulty of removing the anti-rust cover from the dust cover. This kind of anti-rust cover is, in addition, normally located in a very narrow space, within the wheel filled with some other deterrent parts, sandwiched between the disc rotor and the wheel disc, making it extremely difficult or troublesome to insert or reach one's hand into this narrow place or to handle it by lying on one's back beneath the vehicle chassis.
If and when the vehicle is placed in operations a severe condition, results if the anti-rust cover is not removed an accumulation of heat is liable to occur within the anti-rust cover as a result of the heat produced by the braking operation on the disc rotor, and an insufficient heat dissipation therein often overheats the disc rotor deteriorating the braking effect and sometimes causing the anti-rust cover itself to burn.